Palladium containing grafted polyethylene films as catalysts for hydrogenation of unsaturated compounds

A. Abdel Aal1,2, V.V. Khutoryanskiy2, G.A. Mun2, Z.S. Nurkeeva2 and Zh.Kh. Tashmukhambetova3

1Central Metallurgical Research & Development Institute (CMRDI), Hellwan 87, Cairo, Egypt

2 Department of Chemical Physics & Macromolecular Chemistry, Kazakh National University, Karasai Batyra 95, 480012 Almaty, Kazakhstan

3 Department of Catalysis, Petrochemistry and Colloid chemistry, Kazakh National University, Karasai Batyra 95, 480012 Almaty, Kazakhstan

Abstract

Radiation-chemical grafting of cationic vinyl ether of monoethanolamine (VEMEA) on polyethylene films has been performed. The grafting of VEMEA on PE was confirmed by FTIR spectroscopic examination. New bands in the area 1089-1110 cm-1, characteristic for vibrations of ether groups of VEMEA, 1576-1595, 3368 and 3300 cm-1, responsible for deformation and valent vibrations of VEMEA primary amino-groups, are observed in the spectra of grafted films.

New palladium-containing polymeric catalysts were prepared by treatment of the grafted films with solution of sodium tetrachloropalladate. The effect of pH and NaCl concentration in solution on the complex formation between grafted films and sodium tetrachloropalladate is investigated. It was shown that the inorganic salt uptake is higher in acidic media because of the protonation of amino-groups of VEMEA. Sodium tetrachloropalladate uptake by the grafted films is a complex function of NaCl concentration in solution. An increase in NaCl concentration in solution leads to higher values of Na2[PdCl4] uptake at relatively low concentration of the salt (0-0.2 mol/L). Then the further addition of NaCl to the solution decreases the sorption ability of the films. The catalytic activity and selectivity of prepared composites for hydrogenation of model substrate 3-methyl-1-butyne-3-ol were examined. It was shown that the composites with higher grafting degree of VEMEA lead to a higher rate of hydrogen uptake.